
#include<iostream>
#include<map>
#include<vector>
#include<string>
using namespace std;
bool isUnique(string astr) {
    if (astr.size() > 26)
        return false;
    int n = 0;
    for (char ch : astr) {
        int x = ch - 'a';
        if (((n >> x) & 1) == 0)
            n |= (1 << x);
        else
            return false;
    }
    return true;
}
int subarraySum(vector<int>& nums, int k) {
    int sum = 0, count = 0;
    map<int, int> dp;
    dp[0] = 1;
    for (auto ch : nums)
    {
        sum += ch;
        if (dp.count(sum - k)) count += dp[sum - k];
        dp[sum]++;
    }
    return count;
}
int main()
{
    isUnique("abc");
    return 0;
}

